Coordinate measurement machine with redundant energy sources

ABSTRACT

An articulated arm coordinate measurement machine is provided with a power supply having multiple power sources. The power supply having an input configured to receive electrical power from an external energy supply and first and second energy storage members. The first energy storage member having a first processing circuit configured to measure at least one first parameter and transmit a first signal to the first electronic circuit. The second energy storage member having a second processing circuit configured to measure at least one second parameter and transmit a second signal to the first electronic circuit. Wherein the power supply is configure to selectively transfer electrical power from at least one of the first and second energy storage members, the power supply further being configured to change the transfer of electrical power from the first and second energy storage members in response to the first signal and second signal.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S.application Ser. No. 14/868,610 filed on Sep. 29, 2015, which claims thebenefit of U.S. Provisional Application Ser. No. 62/061,225 filed onOct. 8, 2014, the contents of which are incorporated herein by referencein its entirety.

BACKGROUND

The present disclosure relates to a coordinate measuring machine andmore particularly to a portable articulated arm coordinate measuringmachine having redundant onboard power sources.

Portable articulated arm coordinate measuring machines (AACMMs) havefound widespread use in the manufacturing or production of parts wherethere is a need to rapidly and accurately verify the dimensions of thepart during various stages of the manufacturing or production (e.g.,machining) of the part. Portable AACMMs represent a vast improvementover known stationary or fixed, cost-intensive and relatively difficultto use measurement installations, particularly in the amount of time ittakes to perform dimensional measurements of relatively complex parts.Typically, a user of a portable AACMM simply guides a probe along thesurface of the part or object to be measured. The measurement data arethen recorded and provided to the user. In some cases, the data areprovided to the user in visual form, for example, three-dimensional(3-D) form on a computer screen. In other cases, the data are providedto the user in numeric form, for example when measuring the diameter ofa hole, the text “Diameter=1.0034” is displayed on a computer screen.

An example of a prior art portable articulated arm CMM is disclosed incommonly assigned U.S. Pat. No. 5,402,582 ('582), which is incorporatedherein by reference in its entirety. The '582 patent discloses a 3-Dmeasuring system comprised of a manually-operated articulated arm CMMhaving a support base on one end and a measurement probe at the otherend. Commonly assigned U.S. Pat. No. 5,611,147 ('147), which isincorporated herein by reference in its entirety, discloses a similararticulated arm CMM. In the '147 patent, the articulated arm CMMincludes a number of features including an additional rotational axis atthe probe end, thereby providing for an arm with either a two-two-two ora two-two-three axis configuration (the latter case being a seven axisarm).

Three-dimensional surfaces may be measured using non-contact techniquesas well. One type of non-contact device, sometimes referred to as alaser line probe, emits a laser light either on a spot, or along a line.An imaging device, such as a charge-coupled device (CCD) for example, ispositioned adjacent the laser to capture an image of the reflected lightfrom the surface. The surface of the object being measured causes adiffuse reflection. The image on the sensor will change as the distancebetween the sensor and the surface changes. By knowing the relationshipbetween the imaging sensor and the laser and the position of the laserimage on the sensor, triangulation methods may be used to measure pointson the surface.

While existing CMM's are suitable for their intended purposes, what isneeded is a portable AACMM that has certain features of embodiments ofthe present invention.

SUMMARY

In accordance with one embodiment of the invention, a method ofoperating a portable articulated arm coordinate measuring machine(AACMM) for measuring three-dimensional coordinates of an object inspace is provided. The method includes: providing the AACMM in a AACMMframe of reference having an origin, the AACMM having a manuallypositionable arm portion, a base, a noncontact measurement device, thearm portion having an opposed first end and second end, the arm portionincluding a plurality of connected arm segments, each of the pluralityof connected arm segments including at least one position transducer forproducing a plurality of position signals, the first end connected tothe base; providing a first electronic circuit configured for receivingthe position signal from the at least one transducer and for providingdata corresponding to a position of the measurement device, the firstelectronic circuit having a first processor; providing a power supplyhaving an input configured to receive electrical power from an externalenergy supply, a first energy storage member and a second energy storagemember; selectively transferring electrical power at least one of thefirst energy storage member or the second energy storage member whenelectrical power is not available from the external energy supply;storing electrical power in at least one of the first energy storagemember or the second energy storage member when electrical power isavailable from the external energy supply; measuring at least oneparameter the first energy storage member and the second energy storagemember each having a processing circuit configured to that measures oneor more parameters associated with the respective first energy storagemember and the second energy storage member; transmitting a first signalfrom the processing circuit to the first electronic circuit, the firstsignal including the one or more measured parameters; and changing thetransfer of electrical power the first energy storage member or thesecond energy storage member in response to the first signal.

In accordance with one embodiment of the invention, an articulated armcoordinate measurement machine (AACMM) is provided. The AACMM having amanually positionable arm portion, a base, a noncontact measurementdevice, and an electronic circuit, the arm portion having an opposedfirst end and second end, the arm portion including a plurality ofconnected arm segments, each of the plurality of connected arm segmentsincluding at least one position transducer for producing a plurality ofposition signals, the first end connected to the base. A firstelectronic circuit is configured for receiving the position signal fromthe at least one transducer and for providing data corresponding to aposition of the measurement device, the first electronic circuit havinga first processor. A power supply is provided having an input configuredto receive electrical power from an external energy supply, a firstenergy storage member and a second energy storage member. The firstenergy storage member has a first processing circuit configured tomeasure at least one first parameter of the first energy storage member,the first processing circuit configured to transmit a first signal tothe first electronic circuit. The second energy storage member has asecond processing circuit configured to measure at least one secondparameter of the second energy storage member, the second processingcircuit configured to transmit a second signal to the first electroniccircuit. Wherein the power supply is configured to selectively transferelectrical power from at least one of the first energy storage memberand the second energy storage member, the power supply further beingconfigured to change the transfer of electrical power from the firstenergy storage member and second energy storage member in response tothe first signal and second signal.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings, exemplary embodiments are shown whichshould not be construed to be limiting regarding the entire scope of thedisclosure, and wherein the elements are numbered alike in severalFIGURES:

FIG. 1 and FIG. 2 are perspective views of a portable articulated armcoordinate measuring machine (AACMM) having embodiments of variousaspects of the present invention therewithin;

FIG. 3, is a block diagram of electronics data processing systemutilized as part of the AACMM of FIG. 1 in accordance with anembodiment;

FIG. 4 and FIG. 5 are block diagrams of an encoder assembly for thearticulated arm of the AACMM of FIG. 1 in accordance with an embodimentof the invention;

FIGS. 6A and 6B are a block diagram of the probe end electronics of theAACMM of FIG. 1;

FIG. 7 is a schematic diagram of a portion of the probe end electronicsof FIG. 6B;

FIG. 8 is a schematic diagram of another portion of the probe endelectronics of FIG. 6B;

FIG. 9 is a block diagram of the electronic data processing system inaccordance with an embodiment of the invention;

FIGS. 10A and 10B are a block diagram of a power supply having aredundant energy source for use with the AACMM of FIG. 1 in accordancewith an embodiment of the invention;

FIG. 11 is a side illustration of the probe end with the handlepartially disassembled in accordance with an embodiment of theinvention; and

FIG. 12 and FIG. 13 are perspective views illustrating the probe end 103with non-contact measurement devices attached.

DETAILED DESCRIPTION

Portable articulated arm coordinate measuring machines (“AACMM”) areused in a variety of applications to obtain measurements of objects.Embodiments of the present invention provide advantages in allowing anoperator to easily and quickly couple accessory devices that usestructured light to a probe end of the AACMM to provide for thenon-contact measurement of a three-dimensional object. Embodiments ofthe present invention provide further advantages in providing forcommunicating data representing a distance to an object measured by theaccessory. Embodiments of the present invention provide still furtheradvantages in providing power and data communications to a removableaccessory without having external connections or wiring. Embodiments ofthe present invention further provide for a selectively configurable busthat may be operated under different communications protocols inresponse to the accessory coupled to the probe end. Still furtherembodiments of the invention provide for a power supply having redundantenergy sources that allows for replacement of an energy source withoutinterrupting operation of the AACMM.

FIGS. 1 and 2 illustrate, in perspective, an AACMM 100 according tovarious embodiments of the present invention, an articulated arm beingone type of coordinate measuring machine. As shown in FIGS. 1 and 2, theexemplary AACMM 100 may comprise a six or seven axis articulatedmeasurement device having a probe end 103 that includes a measurementprobe housing 102 coupled to an arm portion 104 of the AACMM 100 at oneend. The arm portion 104 comprises a first arm segment 106 coupled to asecond arm segment 108 by a first grouping of bearing cartridges 110(e.g., two bearing cartridges). A second grouping of bearing cartridges112 (e.g., two bearing cartridges) couples the second arm segment 108 tothe measurement probe housing 102. A third grouping of bearingcartridges 114 (e.g., three bearing cartridges) couples the first armsegment 106 to a base 116 located at the other end of the arm portion104 of the AACMM 100. Each grouping of bearing cartridges 110, 112, 114provides for multiple axes of articulated movement. Also, the probe end103 may include a measurement probe housing 102 that comprises the shaftof an axis of rotation for the AACMM 100 (e.g., a cartridge containingan encoder system that determines movement of the measurement device,for example a probe 118, in an axis of rotation for the AACMM 100). Inthis embodiment, the probe end 103 may rotate about an axis extendingthrough the center of measurement probe housing 102. In use of the AACMM100, the base 116 is typically affixed to a work surface.

Each bearing cartridge within each bearing cartridge grouping 110, 112,114 typically contains an encoder system (e.g., an optical angularencoder system). The encoder system (i.e., transducer) provides anindication of the position of the respective arm segments 106, 108 andcorresponding bearing cartridge groupings 110, 112, 114 that alltogether provide an indication of the position of the probe 118 withrespect to the base 116 (and, thus, the position of the object beingmeasured by the AACMM 100 in a certain frame of reference—for example alocal or global frame of reference). The arm segments 106, 108 may bemade from a suitably rigid material such as but not limited to a carboncomposite material for example. A portable AACMM 100 with six or sevenaxes of articulated movement (i.e., degrees of freedom) providesadvantages in allowing the operator to position the probe 118 in adesired location within a 360° area about the base 116 while providingan arm portion 104 that may be easily handled by the operator. However,it should be appreciated that the illustration of an arm portion 104having two arm segments 106, 108 is for exemplary purposes, and theclaimed invention should not be so limited. An AACMM 100 may have anynumber of arm segments coupled together by bearing cartridges (and,thus, more or less than six or seven axes of articulated movement ordegrees of freedom).

The probe 118 is detachably mounted to the measurement probe housing102, which is connected to bearing cartridge grouping 112. A handle 126is removable with respect to the measurement probe housing 102 by wayof, for example, a quick-connect interface (FIG. 10A and FIG. 10B). Aswill be discussed in more detail below, the handle 126 may be replacedwith another device configured to provide non-contact distancemeasurement of an object, thereby providing advantages in allowing theoperator to make both contact and non-contact measurements with the sameAACMM 100. In one embodiment, the non-contacting measurement device maybe a laser line probe or structure light image scanner 400 (FIGS.12-13). In exemplary embodiments, the probe 118 is a contactingmeasurement device and is removable. The probe 118 may have differenttips 118 that physically contact the object to be measured, including,but not limited to: ball, touch-sensitive, curved and extension typeprobes. In other embodiments, the measurement is performed, for example,by a non-contacting measurement device such as an interferometer or anabsolute distance measurement (ADM) device. In an embodiment, the handle126 is replaced with the laser line probe or the coded structured lightscanner device using the quick-connect interface. Other types ofmeasurement devices may replace the removable handle 126 to provideadditional functionality. Examples of such measurement devices include,but are not limited to, one or more illumination lights, a temperaturesensor, a thermal scanner, a bar code scanner, a projector, a paintsprayer, a camera, or the like, for example. In some embodiments, acombination of the foregoing measurement devices may be coupled to theAACMM 100 simultaneously.

As shown in FIGS. 1 and 2, the AACMM 100 includes the removable handle126 that provides advantages in allowing accessories or functionality tobe changed without removing the measurement probe housing 102 from thebearing cartridge grouping 112. As discussed in more detail below withrespect to FIG. 6A and 6B, the removable handle 126 may also include anelectrical interface that allows electrical power and data to beexchanged with the handle 126 and the corresponding electronics locatedin the probe end 103.

In various embodiments, each grouping of bearing cartridges 110, 112,114 allow the arm portion 104 of the AACMM 100 to move about multipleaxes of rotation. As mentioned, each bearing cartridge grouping 110,112, 114 includes corresponding encoder systems, such as optical angularencoders for example, that are each arranged coaxially with thecorresponding axis of rotation of, e.g., the arm segments 106, 108. Theoptical encoder system detects rotational (swivel) or transverse (hinge)movement of, e.g., each one of the arm segments 106, 108 about thecorresponding axis and transmits a signal to an electronic dataprocessing system within the AACMM 100 as described in more detailherein below. Each individual raw encoder count is sent separately tothe electronic data processing system as a signal where it is furtherprocessed into measurement data. No position calculator separate fromthe AACMM 100 itself (e.g., a serial box) is required, as disclosed incommonly assigned U.S. Pat. No. 5,402,582 ('582).

The base 116 may include an attachment device or mounting device 120.The mounting device 120 allows the AACMM 100 to be removably mounted toa desired location, such as an inspection table, a machining center, awall or the floor for example. In one embodiment, the base 116 includesa handle portion 122 that provides a convenient location for theoperator to hold the base 116 as the AACMM 100 is being moved. In oneembodiment, the base 116 further includes a movable cover portion 124that folds down to reveal a user interface, such as a display screen.

In accordance with an embodiment, the base 116 of the portable AACMM 100contains or houses an electronic circuit having an electronic dataprocessing system that includes: a base processing system that processesthe data from the various encoder systems within the AACMM 100 as wellas data representing other arm parameters to support three-dimensional(3-D) positional calculations; and a user interface processing system,an optional display, and resident application software that allows foroperation of the AACMM 100. In one embodiment, the application softwareallows for relatively complete metrology functions to be implementedwithin the AACMM 100 without the need for connection to an externalcomputer.

The electronic data processing system in the base 116 may communicatewith the encoder systems, sensors, and other peripheral hardware locatedaway from the base 116 (e.g., a noncontact distance measurement devicethat can be mounted to the removable handle 126 on the AACMM 100). Theelectronics that support these peripheral hardware devices or featuresmay be located in each of the bearing cartridge groupings 110, 112, 114located within the portable AACMM 100.

FIG. 3 is a block diagram of electronics inside base 116 utilized in anAACMM 100 in accordance with an embodiment. The embodiment shown in FIG.3 includes an electronic data processing system 210 including a baseprocessor 204 for implementing the base processing system, a userinterface board 202, and a base power circuit 206 for providing power.The electronic data processing system 210 may further include wirelesscommunications circuits, such as a Bluetooth module or a Wifi module(not shown). The user interface board 202 may include a computerprocessor for executing application software to perform user interface,display, and other functions described herein.

In the exemplary embodiment, the electronic data processing system 210includes a first Ethernet communications module 220 that allows the baseprocessor 204 to communicate with external devices, such as via a localarea network for example. The electronic data processing system 210further includes a second Ethernet communications module 222. TheEthernet module 222 is coupled for communication with an interface 224that connects the Ethernet module 222 to the arm bus 242. As will bediscussed in more detail herein, the connection 226 allows forcommunication via Gigabit Ethernet protocols. The interface 224 furtherconnects the arm bus 218 with a trigger and capture module 236 thataccepts signals from the probe end 103 related to the actuation ofbuttons and the capturing of coordinate data. The interface 224 furtherconnects the arm bus 218 with an RS-485 transceiver 238. As will bediscussed in more detail herein, the transceiver 238 receives signalsfrom a first bus that is coupled to each of the encoders within thearticulated arm. In one embodiment, the signals received by thetransceiver 238 are transmitted by a module 245 to the base processor204 via a universal serial bus (USB) connection.

The electronic data processing system 210 is in communication with theaforementioned plurality of encoder systems via a portion of the bus218. As will be discussed in more detail below, in the exemplaryembodiment, each of the encoder systems is coupled to a first bus 242that communicates data using the RS-485 protocol. In the embodimentdepicted in FIG. 4 and FIG. 5, each encoder system generates encoderdata and includes: an encoder arm bus interface 214, an encoder digitalsignal processor (DSP) 216, an encoder read head interface 234, and atemperature sensor 212. Other devices, such as strain sensors, may beattached to the encoder arm bus interface 214.

Now referring to FIG. 6A and FIG. 6B, the probe end electronics 230 arein communication with the arm bus 218. The probe end electronics 230include a probe end processor 228, a temperature sensor 212, ahandle/button interface 240 that connects with the handle 126 or thenoncontact distance measurement device 400 via the quick-connectinterface in an embodiment, and a probe interface 226. The quick-connectinterface 247 (FIG.11) allows access by the handle 126 to the data bus,control lines, and power bus used by the noncontact distance measurementdevice 400 and other accessories. In an embodiment, the probe endelectronics 230 are located in the measurement probe housing 102 on theAACMM 100. In an embodiment, the handle 126 may be removed from thequick-connect interface 247 (FIG. 11) and measurement may be performedby the noncontact distance measurement device 400 communicating with theprobe end electronics 230 of the AACMM 100 via the interface bus 218.The quick-connect interface 246 may be the same as that described incommonly owned United States Patent Publication 2013/0125408, thecontents of which are incorporated herein by reference. In anembodiment, the electronic data processing system 210 is located in thebase 116 of the AACMM 100, the probe end electronics 230 are located inthe measurement probe housing 102 of the AACMM 100, and the encodersystems are located in the bearing cartridge groupings 110, 112, 114.The probe interface 226 may connect with the probe end processor 228 byany suitable communications protocol, including commercially-availableproducts from Maxim Integrated Products, Inc. that embody the 1-wire®communications protocol.

As discussed above, the arm bus 218 is comprised of a plurality ofbusses that may be selectively configured to cooperate and operate underdifferent communications protocols. In the exemplary embodiment, the armbus 218 is comprised of a first bus 242, a second bus 246, a third bus248. The first bus 242 is a two wire bus that is configured to operateusing the RS-485 communications protocol. The first or “A” bus 242 iscoupled between the processor 228 and the electronic data processingsystem 210 and each encoder interface 214. In this way, the first bus242 transmits encoder data that allows the electronic data processingsystem to determine the position and orientation of the probe end 103and thus the coordinates of a measured point or points. The second or“B” bus 244 is also a two-wire bus. Referring to FIG. 7 with continuingreference to FIG. 6A and FIG. 6B, the third or “C” bus 246 isselectively coupled using X and Y signals 249 by a switch 250 to allowdirect transmission of data from the combined Bus B 244 and Bus C 246 tothe processor 228. The X and Y signals 249 may be generated by theprocessor in response to receiving LLPID0 and LLPID1 signals 251 fromthe attached accessory device, such as the laser line probe. The LLPIP0and LLPIP1 signals 251 are transmitted by the accessory device tofacilitate identification of the accessory device by the processor 228.In the exemplary embodiment, the accessory identification data may besubsequently relayed to the base processor 204 via bus 242. When theLLPID0 and LLPID1 signals 251 identify an accessory device whichsupports 10/100 Ethernet, the switch 252 defines a connection from theaccessory device (i.e. LLP) to allow signals from the accessory deviceto be transmitted directly to bus 246 without first transmitting throughprocessor 228.

In other embodiments, the X and Y signals 249 may be generated by thebase processor 204 and transmitted to the switch 250. In one embodiment,the signals 249 may be transmitted by the base processor 204 in responseto an input by the operator via an AACMM user interface. In still otherembodiments, the LLPID0 AND LLPID1 signals 251 may be transmitteddirectly from the accessory device (i.e. LLP) to the switch 250. Itshould be appreciated that advantages may be gained by receiving thesignals 251 with the processor 228 in that testing may be performedprior to providing a direct connection between the accessory device andthe bus 246.

It should be appreciated that while the first bus 242 is capable oftransferring data at 6.25 Mb/s, the logical bus formed by thecombination of the second bus 246 up to 100 Mb/s using the 10/100Ethernet communications protocol. Such an increase in capacity may bedesired for some accessory devices, such as the laser line probe 300 forexample, which acquires an increased amount of data when compared with atouch probe.

The fourth or “D” bus 248 is a four-wire bus. Referring now to FIG. 8with continuing reference to FIG. 6A and FIG. 6B, the fourth bus 248 isconnected to a second switch 252 that selectively configures the fourthbus 248 to cooperatively operate with the second bus 246 and third bus248 (which are selectively coupled via switch 252) to define a logicaleight-wire bus that is configured to communicate using the GigabitEthernet protocol. It should be appreciated that the logical eight-wirebus is capable of transferring data at a rate of up to 1 Gb/s. It isanticipated that in operation the logical eight-wire bus will operate ata data transfer rate of about 500 Mb/s. This increased capacity may bedesirable with certain accessories coupled to the probe end 103, such asnon-contact measurement devices that capture image data at highresolutions, video cameras or multiple accessories coupled to the probeend and operated simultaneously.

In operation, the activation of the switches 250, 252 may be in responseto a signal from the electronic data processing system 210 or the probeend processor 228. In one embodiment, the activation of the switches250, 252 may be in response to an input by an operator, such as throughuser interface 202 for example, indicating that a particular accessorydevice has been coupled to the probe end 103. In another embodiment, theprobe end processor 228 detects the connection of an accessory devicecapable of transmitting large amounts of data and activates the switches250, 252 to configure a logical bus that is appropriate for theconnected accessory device. It should be appreciated that the activationof the switches 250, 252 may be in response to a signal from the probeend processor 228, based on LLPID0 and LLPID1, the base processor 204 ora combination of the foregoing. One advantage of switches 250, 252 isthat it allows the selective creation of logical buses to providebackwards compatibility with accessories to match the communicationsprotocol utilized by that accessory device.

In the exemplary embodiment, the articulated arm 100 includes one ormore slip ring devices that are configured to transmit electrical powerand data across a rotational joint, such at each cartridge grouping 110,112, 114. In one embodiment, the cartridge grouping 110 includes twoslip ring devices, cartridge grouping 112 may include one slip ringdevice (6-axis AACMM) or two slip ring devices (7-axis AACMM), while thecartridge grouping 114 includes three slip ring devices. It should beappreciated that the bus 218 traverses each of these rotational joints.In one embodiment, each slip ring device is configured to transfer 18connections (wires). These connections include six connections for thefirst bus 242, second bus 244 and third bus 246 and four connections forthe fourth bus 248. In addition, there are eight connections forelectrical power, capture and trigger. In the exemplary embodiment, theeighteen connections are divided into two connectors. An exemplary slipring device is model number SRA-73820-1 manufactured by Moog, Inc.

In one embodiment shown in FIG. 9, the base processor board 204 includesthe various functional blocks. For example, a base processor function302 is utilized to support the collection of measurement data from theAACMM 100 and receives raw arm data (e.g., encoder system data) via thearm bus 218 and a bus control module function 308. The memory function304 stores programs and static arm configuration data. The baseprocessor board 204 also includes an external hardware option portfunction 310 for communicating with any external hardware devices oraccessories. A real time clock (RTC) and log 306 and a diagnostic port318 are also included in the functionality in an embodiment of the baseprocessor board 204 depicted in FIG. 9.

The base processor board 204 also manages all the wired and wirelessdata communication with external (host computer) and internal (userinterface 202) devices. The base processor board 204 has the capabilityof communicating with an Ethernet network via an Ethernet function 320,with a wireless local area network (WLAN) via a IEEE 802.11 LAN function322, and with Bluetooth module 232 via a parallel to serialcommunications (PSC) function 314. The base processor board 204 alsoincludes a connection to a universal serial bus (USB) device 312.

The base processor board 204 transmits and collects raw measurement data(e.g., encoder system counts, temperature readings) for processing intomeasurement data without the need for any preprocessing, such asdisclosed in the serial box of the aforementioned '582 patent. In anembodiment, the base processor 204 also sends the raw measurement datato an external computer.

The electronic data processing system 210 shown in FIG. 9 also includesa base power circuit 206 with an environmental recorder 362 forrecording environmental data. The base power circuit 206 also providespower to the electronic data processing system 210 using an AC/DCconverter 358 and a battery charger control 360. The base power circuit206 communicates with the base processor board 204 usinginter-integrated circuit (I2C) serial single ended bus 354 as well asvia a DMA serial peripheral interface (DSPI) 357. The base power circuit206 is connected to a tilt sensor and radio frequency identification(RFID) module 208 via an input/output (I/O) expansion function 364implemented in the base power circuit 206.

In one embodiment shown in FIG. 10A and FIG. 10B, the base power circuit206 includes an input filter 366 that receives power from an energysource 367 (e.g. a wall outlet) and transfers the electrical power tothe battery charger control 360. In this embodiment, the battery chargercontrol 360 is electrically coupled to a first energy storage device anda second energy storage device, such as first battery 368 and secondbattery 370. The battery charger control 360 is configured to transferelectrical power to (e.g. charge the batteries) and receive electricalpower from the batteries 368, 370. Each of the batteries 368, 370includes a processing circuit 372 that monitors the voltage, currentdrain, and battery temperature via sensors (not shown) in the respectivebattery 368, 370. The battery charger control 360 is further coupled tocommunicate with each processing circuit 372 via a SMBus (I2C) 374 toreceive signals indicating the status of each battery 368, 370.

In one embodiment, the battery charger control 360 is configured tocharge one or both of the batteries in response to a signal from theprocessing circuits 372 when AC electrical power is present. In oneembodiment, the battery charger control 360 (the dual battery smartcharger 360) may be configured to charge or withdraw electrical powerfrom one or both of the batteries 368, 370 to optimize a parameter, suchas battery life or operation time, based on signals from the processors372. The battery charger control 360 may further be configured toselectively withdraw electrical power from one or both of the batteries368, 370. In one embodiment, the battery charger control 360 transmitsbattery data to the base processor 204.

In the exemplary embodiment, the batteries 368, 370 are each removablycoupled to the AACMM 100. The batteries 368, 370 and the battery chargercontroller 360 may be configured to allow removal of one or both of thebatteries during operation without interrupting the operation of theAACMM 100. When operating solely on battery power, one of the batteries368, 370 may be removed while the AACMM 100 is operated using electricalpower from the other battery (e.g. hot swappable). It should beappreciated that this dual battery arrangement provides a number ofadvantages in that the batteries provide a redundant power supply forthe AACMM 100 in the event that AC electrical power from the energysource 367 is removed or otherwise lost. The dual battery arrangementalso provides advantages in allowing extended, uninterrupted, operationunder battery power since as batteries are drained/depleted, thedepleted battery may be removed and replaced with a new fully chargedbattery. In this way, so long as replacement batteries are available,operation under battery power may extend indefinitely. It should beappreciated that further advantages are gained since the battery may berecharged while uncoupled from the AACMM 100. Further, advantages may begained in extending the useful life of the batteries 368, 370 byoperating the battery charger control 360 to lower the average currentwithdrawn from each battery during operation.

Electrical power is transferred from the battery charger control 360 toa conditioning module 376 that also interfaces with a power actuator378. The power actuator 378 allows the operator to selectively turn theAACMM 100 on or off. The power conditioning module 376 transfers aportion of the electrical power to the environmental recorder 362. Theremaining electrical power is transferred to a buck-boost module 380 anda buck regulator module 382, which adapt the electrical power to havecharacteristics suitable for use by the electronic data processingsystem 210.

Though shown as separate components, in other embodiments all or asubset of the components may be physically located in differentlocations and/or functions combined in different manners than that shownin FIG. 3. For example, in one embodiment, the base processor board 204and the user interface board 202 are combined into one physical board.

Referring now to FIGS. 12-13, an exemplary embodiment of a probe end 103is illustrated having a measurement probe housing 102 with aquick-connect mechanical and electrical interface that allows removaland interchangeability of accessory devices, such as non-contactmeasurement devices 400. In one embodiment, the device 400 is removablycoupled to the probe end 103 via the coupler mechanism and interface426. In another embodiment, the device 400 is integrally connected tothe probe end 103. In the exemplary embodiment, the non-contactmeasurement device 400 may be a laser line probe or a structured lightscanner having a single camera FIG. 12 or two cameras (FIG. 13). Thedevice 400 may also be an interferometer, an absolute distancemeasurement (ADM) device, a focusing meter or another type ofnon-contact distance measurement device.

The device 400 includes an electromagnetic radiation transmitter, suchas a light source 402 that emits coherent or incoherent light, such as alaser light or white light for example. The light from light source 402is directed out of the device 400 towards an object to be measured. Inone embodiment the device 400 has a single camera 404 (FIG. 12) and inanother embodiment has two cameras 404, 406. Each of the cameras mayinclude an optical assembly and an optical receiver. The opticalassembly may include one or more lenses, beam splitters, dichromaticmirrors, quarter wave plates, polarizing optics and the like. Theoptical receiver is configured receive reflected light and theredirected light from the optical assembly and convert the light intoelectrical signals. The light source 402 and the cameras are bothcoupled to a controller 408. The controller 408 may include one or moremicroprocessors, digital signal processors, memory and signalconditioning circuits.

Further, it should be appreciated that the device 400 is substantiallyfixed relative to the probe tip 118 so that forces on the handle portion410 do not influence the alignment of the device 400 relative to theprobe tip 118. In one embodiment, the device 400 may have an additionalactuator (not shown) that allows the operator to switch betweenacquiring data from the device 400 and the probe tip 118.

The device 400 may further include actuators 412 which may be manuallyactivated by the operator to initiate operation and data capture by thedevice 400. In one embodiment, the optical processing to determine thedistance to the object is performed by the controller 408 and thedistance data is transmitted to the electronic data processing system210 via bus 240. In another embodiment optical data is transmitted tothe electronic data processing system 210 and the distance to the objectis determined by the electronic data processing system 210. It should beappreciated that since the device 400 is coupled to the AACMM 100, theelectronic processing system 210 may determine the position andorientation of the device 400 (via signals from the encoders) which whencombined with the distance measurement allow the determination of the X,Y, Z coordinates of the object relative to the AACMM.

In the exemplary embodiment, the AACMM 100 is configured to transferdata between the device 400 and the electronic data processing system210 via one of the buses 242, 244, 246, 248. The bus used will depend onthe accessory device 400 that is coupled to the probe end 103. Theelectronic data processing system 210 or the processor 228 areconfigured to detect the device 400 and determine the data transfer ratedesired for the connected device 400. Once the device 400 is detected, asignal is transmitted to one or both of the switches 250, 252 to createa logical bus having the data transfer and communications protocolcharacteristics desired for operation of the device 400 with the AACMM100. It should be appreciated that the electrical power for operation ofthe device 400 may be provided by the base power circuit 206, such asfrom the batteries 368, 370, or from a power supply arranged internal tothe device 400 (not shown). In still another embodiment, the device 400may be powered via an external power cable.

While the invention has been described with reference to exampleembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments falling within the scope of the appendedclaims. Moreover, the use of the terms first, second, etc. do not denoteany order or importance, but rather the terms first, second, etc. areused to distinguish one element from another. Furthermore, the use ofthe terms a, an, etc. do not denote a limitation of quantity, but ratherdenote the presence of at least one of the referenced item.

What is claimed is:
 1. A method of operating a portable articulated armcoordinate measuring machine (AACMM) for measuring three-dimensionalcoordinates of an object in space, comprising: providing the AACMM, theAACMM having a manually positionable arm portion and a measurementdevice, the arm portion having a plurality of connected arm segmentsthat include at least one position transducer for producing a pluralityof position signals; providing a first electronic circuit configured forreceiving the plurality of position signals from the at least oneposition transducer and for providing data corresponding to a positionof the measurement device; and providing a power supply having an inputconfigured to receive electrical power from an external energy supply,and a first energy storage member and a second energy storage memberelectrically coupled to the first electronic circuit, wherein the firstenergy storage member is removably coupled to the AACMM, each of firstenergy storage member and the second energy storage member include aprocessing circuit configured to measure one or more parameters;selectively transferring electrical power with the power supply from atleast one of the external energy supply, the first energy storage memberor the second energy storage member; storing electrical power in atleast one of the first energy storage member or the second energystorage member when electrical power is available from the externalenergy supply; measuring at least one parameter of the one or moreparameters with at least one of the processing circuits; transmitting afirst signal from the at least one of the processing circuits to thefirst electronic circuit, the first signal including the at least oneparameter; and changing the transfer of electrical power between thefirst energy storage member and the power supply in response to thefirst signal.
 2. The method of claim 1 wherein the step of measuring atleast one parameter includes measuring one or more of the voltage,current drain and temperature of the first energy storage member.
 3. Themethod of claim 1 wherein the step of changing the transfer ofelectrical power includes the step of changing the transfer ofelectrical power to increase battery life.
 4. The method of claim 1wherein the step of changing the transfer of electrical power includesthe step of changing the transfer of electrical power to increasebattery operating time.
 5. The method of claim 1 further comprisinguncoupling the first energy storage member from the power supply whilethe power supply is transferring electrical power from the externalenergy supply to the first electronic circuit without interruptingoperation of the AACMM.
 6. The method of claim 5 further comprisinguncoupling the first energy storage member from the power supply whiletransferring electrical power from the second energy storage memberwithout interrupting operation of the AACMM.
 7. The method of claim 6further comprising charging the first energy storage member whileuncoupled from the power supply.
 8. The method of claim 7 furthercomprising coupling the first energy storage member to the power supplywhile transferring electrical power from the second energy storagemember.
 9. An articulated arm coordinate measurement machine (AACMM)comprising: a manually positionable arm portion a measurement device,and an electronic circuit, the arm portion having a plurality ofconnected arm segments that include at least one position transducer forproducing a plurality of position signals; a first electronic circuitconfigured for receiving the plurality of position signals from the atleast one position transducer and for providing data corresponding to aposition of the measurement device; a power supply having an inputconfigured to receive electrical power from an external energy supply, afirst energy storage member and a second energy storage member, thefirst energy storage member and second energy storage member beingelectrically coupled to the first electronic circuit; the first energystorage member being removably coupled to the power supply, the firstenergy storage member having a first processing circuit that measures atleast one first parameter of the first energy storage member, the firstprocessing circuit transmitting a first signal to the first electroniccircuit in response to measuring the at least one first parameter; thesecond energy storage member operably coupled to the power supply, thesecond energy storage member having a second processing circuit thatmeasures at least one second parameter of the second energy storagemember, the second processing circuit transmitting a second signal tothe first electronic circuit in response to measuring the at least onesecond parameter; wherein the power supply selectively transferselectrical power from at least one of the external energy supply, thefirst energy storage member and the second energy storage member, thepower supply further transferring of electrical power from one of thefirst energy storage member and the second energy storage member to thefirst electronic circuit in response to the first signal and the secondsignal.
 10. The AACMM of claim 9 wherein the power supply is configuredin operation to allow removal of at least one of the first energystorage member and the second energy storage member when electricalpower is being transferred from the external energy supply.
 11. TheAACMM of claim 10 wherein the power supply is configured in operation toallow removal of one of the first energy storage member and the secondenergy storage member when electrical power is being transferred fromthe other of the first energy storage member and the second energystorage member.
 12. The AACMM of claim 11 wherein the first processingcircuit and the second processing circuit are each configured to measureone or more of the voltage, current drain and temperature.
 13. The AACMMof claim 9 wherein the power supply changes the transfer of electricalpower to reduce an average current withdrawn from each of the firstenergy storage member and the second energy storage member duringoperation.
 14. The AACMM of claim 9 wherein the power supply includes abase power circuit coupled for communication between the firstprocessing circuit and the first electronic circuit.
 15. The AACMM ofclaim 14 wherein the base power circuit is coupled for communication tothe first processing circuit by an inter-integrated circuit (I2C) serialsingle ended bus.
 16. The AACMM of claim 15 wherein the first processingcircuit is coupled to communicate with the base power circuit via a I2Cserial bus.
 17. A method of operating a portable articulated armcoordinate measuring machine (AACMM) for measuring three-dimensionalcoordinates of an object in space, comprising: providing the AACMM in aAACMM frame of reference having an origin, the AACMM having a manuallypositionable arm portion, a base, a noncontact measurement device, thearm portion having an opposed first end and second end, the arm portionincluding a plurality of connected arm segments, each of the pluralityof connected arm segments including at least one position transducer forproducing a plurality of position signals, the first end connected tothe base; providing a first electronic circuit configured for receivingthe plurality of position signals from the at least one positiontransducer and for providing data corresponding to a position of thenoncontact measurement device, the first electronic circuit having afirst processor; and providing a power supply having an input configuredto receive electrical power from an external energy supply, a firstenergy storage member and a second energy storage member, wherein thefirst energy storage member and the second energy storage member areremovably coupled to the AACMM; receiving electrical power from one ofthe external energy supply and the first energy storage member with thepower supply; uncoupling the second energy storage member from the powersupply while transferring electrical power from one of the first energystorage member and the external energy supply.
 18. The method of claim17 further comprising charging the second energy storage member externalto the AACMM when the second energy storage member is uncoupled from thepower supply.
 19. The method of claim 17 further comprising coupling thesecond energy storage member to the power supply while transferringelectrical power from one of the first energy storage member and theexternal energy supply.
 20. The method of claim 19 further comprisingstoring electrical power in at least one of the first energy storagemember or the second energy storage member when electrical power isavailable from the external energy supply.